This proposal requests funds for a microscope and image analysis system that will allow analysis of a wide variety of images from many different biological system. The microscope is an old but very powerful instrument for the study of living organisms. Few other biological tools allow subcellular structures, whole cells, or even small organisms to be studied in an aqueous environment, frequently in a living state. New probes for cells structure and function such as fluorescently labelled antibodies, DNA probes, and calcium and pH dependent fluorophores provide even more powerful implements for exploring cells. The computer in combination with the microscope has proven to be a particularly powerful means for acquiring and analyzing data from images. The research projects described in this proposal encompass a variety of biological systems including plant-virus interactions, cyanobacterial development, nerve regeneration, optical pathways, leech development, and wasp evolution. These projects share a need for a system to acquire, enhance, and analyze images.